BlackRX300

My 2001 RX300 has no heat to the cabin.

I have been reading about the Air Mix Servo and how to remove and clean.
My question is: Since there is no heat to the cabin, is this the culprit?
The car does not run hot.
Air will come out of every vent (windshield, floor, middle.)
The blower - blows correctly the the setting from low to high.
Everything seems to work, but no heat.
Also, I do not have the dreaded buzzing noise most speak of.

I have read that there or either two or three servos behind the glove box and want to make sur I am dealing with the right one. (mode, air mix and ???)

Any suggestions, ideas or insight will be appreciated.

Thanks in advance.

salimshah

The mode servo either operates automatically (in Auto) or responds to mode setting and when things are working fine, displays the mode position on the display. Use the mode and move through all settings and verify by feel that the air is being deflected appropriately. In Auto, this servo keeps controlling the flow and can become noisy when things do not move as needed.

Mix servo controls the heat is controlled by cabin temperature a/c-heat. Which seems like the problem you are describing. You can remove the servo and manually move the lever the servo operates to see if you get the heat. All hunches should be verified by test.

Salim

Australian

wondering 2 things if the valve seized or the plugs have snapped off the controls either way it is switched off and closed.

BlackRX300

I did the DIY on my servos Sunday.

Before removing, I checked to see how the servo's moved.
The "mode" servo was working fine and directed the air to defrost, vent and floor fine.
The "air mix" servo would not open the vent door to allow heat into the cabin.

I took both servos out, took them apart, cleaned and re-installed.
The mode servo still directed the air flow, but the air mix servo still would not move the vent door.

Guess I'll be ordering a new Air Mix Servo.

salimshah

One suggestion was to manually move the mix servo arm ... just in case the arm is stuck.

Salim

BlackRX300

I was able to move it manually, but the servo would not move it.
Looks like I need a new servo.

salimshah

Did it get you heat?

If it did, then buying the servo will solve your problem [Problem being no heat]. If you dont get heat then replacing the servo will get the arm moving, but your problem would not be solved.

Salim

BlackRX300

YES.....

After checking it manually with the ignition on, there was HEAT.

I reinstalled the servo with the arm holding the vent door open. Now there is heat all of the time.
I need to replace the servo before summer, or the heat will compete with the A/C.
I only wish cleaning the servo would have worked. Now I have to get in there and remove and replace AGAIN.
At least the next time I know exactly what to do and it shouldn't take as long.